There has been significant growth and developments in domestic applications of fracking during well completion operations. Special downwell equipment and downhole tools have been introduced to support and promote multi-zone production and during fracking operations, but a problem that has persisted is having the capability to efficiently open and close multiple frack stages and/or multiple production zones solely using permanently-placed downhole tools.
Furthermore, in order to promptly selectively shut down a particular frack stage or a particular production zone due to operational problems or change of circumstances, there is a paucity of tools and methodologies for effectively and reliably accomplish this crucial shut-down task without jeopardizing wellbore integrity. As will be readily appreciated by those skilled in that art, common approaches for handling this situation generally involve injecting cement into a wellbore which, unfortunately, shuts down production in all producing zones—not just the particular troublesome production zone. It will be understood that such approach adversely affects the plethora of pores permeating the producing zone and, indeed, requires substantial reworking if production from the wellbore were to be revived.
Those conversant in the art will understand that an intervention step would typically be prerequisite to address the challenge of selectively closing a particular frack stage or production zone in a multiple frack stage or multiple production zone scenario. There appears to have been a paucity of improvements in the art. The commonly used drop ball methodology for fracking seems to inherently preclude such selective opening and closing of stages or zones contemplated herein. Indeed, it should be evident that this drop ball approach precludes such opening and closing, and consequently requires that cementing be invoked to plug a wellbore which, of course, essentially undermines the well's prospects for further production. Sliding sleeve downhole tool embodiments have been applied to promote fracking using a series of plugs urged downhole under pressure. But, this sliding sleeve approach also significantly inhibits opening and closing as contemplated hereunder. Nevertheless, it appears that the heretofore most reliable method for shutting down and sealing a wellbore is to inject cement therein.
Accordingly, what is needed in the art is a downhole tool permanently emplaced within a wellbore using a packer affixed at each end thereof, having the inherent capability to selectively open and close multiple frack stages and multiple production zones without requiring not only a total shutdown of fracking operations or hydrocarbon production, but also just receiving a signal from the well surface that remotely triggers such specific opening and closing, in the absence of an additional intervening and costly step.
In view of these and other known deficiencies in the downhole art, it appears that selective opening and closing of multiple frack stages and multiple production zones has heretofore been and remains nonexistent. Accordingly, these limitations and disadvantages of the prior art are overcome with the present invention, wherein improved means and techniques are provided which are especially useful for using the multi-frac tool of the present invention with its in situ capability to effectively open and close frack stages and production zones.